1. Field of the Invention
The general invention relates to spreaders, and more particularly to a bed mounted spreader having an improved auger design.
2. Description of the Related Art
Conventional rear mounted spreaders have a material delivery system which uses a vertical auger for directing material through an outlet in a hopper. The outlet is typically a circular opening defined by the converging walls of the hopper. Generally, the walls adjacent to the circular opening define a tubular opening and the auger is received within this tubular opening. The blades of the auger are closely adjacent to the walls of this tubular opening. The hopper receives and stores, for example, sand, salt or other materials to be spread. The vertical auger typically rises from the outlet and into the hopper. In conventional spreaders, a rod extends from the auger and attaches to a motor mounted in the hopper that drives the auger.
This type of vertical auger orientation has presented operating problems. Due to moisture or other environmental factors, the material within the hopper can become compacted, particularly adjacent the tubular opening. While the auger effectively directs material contacting the auger through the outlet, the compacted material can cause a cavity to form above the auger preventing material from reaching the auger. Compaction is particularly problematic with sand and bulk salt, which naturally compacts and cavitates in a spreader. Sand and bulk salt will form a cavity directly above the auger and starve the auger.
Further, most related art spreaders are not releasably mounted to a truck bed. These spreaders are integrally formed within the bed and have a conveyor belt extending the entire length of the bed to deliver material to a spinner. One related art spreader, shown in U.S. Pat. No. 5,927,617, has an integrally formed hopper in the bed with a conveyor belt system for delivering the material to the spinner. However, the '617 Patent utilizes a dumping mechanism to deliver the material to the conveyor belt. Another spreader, shown in U.S. Pat. No. 5,690,466, has sloping side walls and a flat bottom that delivers material to an auger which runs the length of the truck bed.
The related art spreaders are characterized by one or more inadequacies. Specifically, none of the related art spreaders provide for a spreader having a large capacity hopper and a frame releasably mounted in the bed of the truck. The frames are typically a single piece that becomes corroded and must be replaced with a entirely new frame. The frames are very heavy and cumbersome and require up to 5 hours to remove from the back of the vehicle. The related art spreaders do not provide adequate devices for preventing cavitation of the material as the material is discharged from the spreader. The spreaders are expensive to manufacture and difficult to maintain due to the auger or the conveyor belt running the length of the truck bed and the dumping mechanisms required to deliver the material to the conveyor. It would be advantageous to provide a spreader that was removable from the truck bed and cost effective to manufacture and easily maintained.